Ext.override(Ext.form.Field,{
	
	/**
	 * Adiciona acessor para readOnly
	 */	
	 setReadOnly: function(readOnly)
	 {
	 	this.readOnly = readOnly;
		
		if(this.el)
		{
			var type = this.el.dom.type||"text";
			if(type == 'password')
			    type = 'text';
		
			this.el.dom.readOnly = readOnly;
			this.el[readOnly ? 'addClass' : 'removeClass']('x-form-'+type+'-readonly');
		}
	 }
	 
});


/**
 * Adiciona classe para readonly
 */
Ext.form.Field.prototype.onRender = Ext.form.Field.prototype.onRender.createSequence(function()
{
	var type = this.el.dom.type||"text";
    if(type == 'password')
        type = 'text';
	
	if(this.readOnly)
        this.el.addClass('x-form-'+type+'-readonly');
});